In the past, there has been proposed a method for recording the image of the shapes of guide rails installed in a hoistway or the image of patterns on surfaces of the guide rails by means of a CCD linear camera for the purpose of detecting the position and/or the speed of a car. The CCD linear camera is mounted on the car that moves up and down along the guide rails (see a first patent document).
First Patent Document    Japanese patent application laid-open No. 2002-274765